diff options
| author | Igor Mammedov <imammedo@redhat.com> | 2020-04-30 11:46:06 -0400 |
|---|---|---|
| committer | Michael Roth <mdroth@linux.vnet.ibm.com> | 2020-06-09 21:25:14 -0500 |
| commit | 34c78a4100c967cc385fcfd4c2295b2b0ebd8786 (patch) | |
| tree | 89169dc78a803a5b58100d41b1ee87c508b69c5a | |
| parent | 8d127b4be723837a8e33fbc9173bc5cd95b4242f (diff) | |
hostmem: don't use mbind() if host-nodes is empty
Since 5.0 QEMU uses hostmem backend for allocating main guest RAM.
The backend however calls mbind() which is typically NOP
in case of default policy/absent host-nodes bitmap.
However when runing in container with black-listed mbind()
syscall, QEMU fails to start with error
"cannot bind memory to host NUMA nodes: Operation not permitted"
even when user hasn't provided host-nodes to pin to explictly
(which is the case with -m option)
To fix issue, call mbind() only in case when user has provided
host-nodes explicitly (i.e. host_nodes bitmap is not empty).
That should allow to run QEMU in containers with black-listed
mbind() without memory pinning. If QEMU provided memory-pinning
is required user still has to white-list mbind() in container
configuration.
Reported-by: Manuel Hohmann <mhohmann@physnet.uni-hamburg.de>
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <20200430154606.6421-1-imammedo@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Cc: qemu-stable@nongnu.org
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
(cherry picked from commit 70b6d525dfb51d5e523d568d1139fc051bc223c5)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
| -rw-r--r-- | backends/hostmem.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/backends/hostmem.c b/backends/hostmem.c index e773bdfa6e..21b1993e49 100644 --- a/backends/hostmem.c +++ b/backends/hostmem.c @@ -363,8 +363,10 @@ host_memory_backend_memory_complete(UserCreatable *uc, Error **errp) assert(sizeof(backend->host_nodes) >= BITS_TO_LONGS(MAX_NODES + 1) * sizeof(unsigned long)); assert(maxnode <= MAX_NODES); - if (mbind(ptr, sz, backend->policy, - maxnode ? backend->host_nodes : NULL, maxnode + 1, flags)) { + + if (maxnode && + mbind(ptr, sz, backend->policy, backend->host_nodes, maxnode + 1, + flags)) { if (backend->policy != MPOL_DEFAULT || errno != ENOSYS) { error_setg_errno(errp, errno, "cannot bind memory to host NUMA nodes"); |